______ the prices of color TV sets down by50%, the company had a very hard time.

Most of the people __________ to the party were famous scientists [ ]

－How long have they __________－For one month.

____all the required papers. he didn’t answer the questions fluently in class.

go on using energy so wastefully, __________ are that our oil wells will be dried up before new energy sources can be found to replace oil.